1. Field of the Invention
The present invention generally relates to an antenna for a portable terminal, and, in particular, to an antenna feed line for a portable terminal.
2. Description of the Related Art
Generally, a “portable terminal” refers to a mobile communication device which enables wireless communications between users or between a user and a service provider through a base station. Applications such as voice communication or Short Message Service (SMS) have been provided to users using portable terminals at the early stages of a mobile communication service, but such services now extend to video communication, moving picture services, mobile banking, and the like as communication technology develops. An antenna is essential for communication with another user via a base station. Moreover, as the mobile communication service extends to a multimedia service such as a moving picture service, the performance of an antenna has become an important barometer of signal quality of the portable terminal.
A conventional antenna generally protrudes outward from the portable terminal. As a result, the antenna is likely to be damaged by external shock or is inconvenient to carry and limits the diversification of the design of the portable terminal. Moreover, recent users have demanded a small portable terminal having an elegant appearance.
Thus, an attempt to install the antenna inside the portable terminal has been made, and most portable terminals now have a built-in antenna. However, there are many difficulties in securing an antenna mounting space inside the portable terminal, and the built-in antenna has a lower electric wave reception sensitivity than a protruding antenna.
For stable operation of the built-in antenna, the antenna is disposed in a lower portion of the portable terminal, and a main board is disposed in an upper portion of the portable terminal, thereby avoiding interference between the antenna and the main board. In addition, a Radio Frequency (RF) cable as a coaxial cable is generally installed to connect an RF end of the main board with a feeder of the antenna.
However, connectors are installed at both ends of the conventional RF cable so that the RF cable can be connected with the main board and the antenna. The connectors may be separated from the RF end or the feeder by external shock applied to the portable terminal, causing an interruption in the stable connection between the antenna and the main board. Furthermore, the conventional RF cable is used to transmit/receive a signal without being completely shielded, resulting in signal loss during signal transmission/reception. Moreover, the RF cable is the conventional axial cable type that is inconvenient to fix inside the portable terminal due to the space requirements of the RF cable.